you might want to make sure the app has the permissions it needs on your phone, if it does not will will not work well
smarthing app (the new one) menu (top left) >settings (top right of the pop up) > linked services > (you can manages it here.
I guess I added mine with old app
this tread says to reinstal lthe new app
her is video
This is how you link it
I guess I just got lucky that mine still works?